I mentioned the other day that I’m looking for early bloomers among the native species. Some — but not all — plants in genus Trillium bloom early. Last year, I saw some on the forest floor that behaved like ephemerals, blooming early and then fading as the trees put on leaves, shading the forest floor.
The trillium looks straightforward, but it’s tricky. As you’d guess by the name, it’s the plant of threes: three leaves, three sepals, three petals.
But the leaves are really bracts, rising from the rhizome. The stem isn’t really a stem but an extension of the rhizome. The above-ground structure — the part of the plant that we see and that I’m struggling to identify — is called a scape. Here’s the U.S. Forest Service’s explanation:
Morphologically, trillium plants produce no true leaves or stems above ground. The “stem” is just an extension of the horizontal rhizome and produces tiny, scale like leaves (cataphylls). The above-ground plant is technically a flowering scape, and the leaf-like structures are bracts subtending the flower. Despite their morphological origins, the bracts have external and internal structure like a leaf, function in photosynthesis, and most authors refer to them as leaves.
I would love to hear Mother Nature explain the evolutionary rationale behind these developments.
I think I ought to have a better understanding of these plants because Georgia is prime territory for them. Of the 38 species in the United States, 22 are found in Georgia. I really should be able to identify a few.
• Source: “About Trilliums,” a publication of the U.S. Forest Service, is here: https://www.fs.usda.gov/wildflowers/beauty/trilliums/about.shtml
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